title: Menin, the product of the MEN1 gene, is a nuclear protein.
abstract: The MEN1 gene, mutations in which are responsible for multiple endocrine neoplasia type 1 (MEN1), encodes a 610-amino acid protein, denoted menin. The amino acid sequence of this putative tumor suppressor offers no clue to the function or subcellular location of the protein. We report herein, based on immunofluorescence, Western blotting of subcellular fractions, and epitope tagging with enhanced green fluorescent protein, that menin is located primarily in the nucleus. Enhanced green fluorescent protein-tagged menin deletion constructs identify at least two independent nuclear localization signals (NLS), both located in the C-terminal fourth of the protein. Among the 68 known independent disease-associated mutations, none of the 22 missense and 3 in-frame deletions affect either of the putative NLS sequences. However, if expressed, none of the truncated menin proteins resulting from the 43 known frameshift/nonsense mutations would retain both the NLSs. The precise role(s) of menin in the nucleus remain to be understood.
authors.affiliation: Genetics and Molecular Biology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Guru
authors.forename: P K
authors.initials: PK
authors.lastname: Goldsmith
authors.forename: A L
authors.initials: AL
authors.lastname: Burns
authors.forename: S J
authors.initials: SJ
authors.lastname: Marx
authors.forename: A M
authors.initials: AM
authors.lastname: Spiegel
authors.forename: F S
authors.initials: FS
authors.lastname: Collins
authors.forename: S C
authors.initials: SC
authors.lastname: Chandrasekharappa
mesh_terms: D000595:Amino Acid Sequence; D002451:Cell Compartmentation; D002467:Cell Nucleus / Q000378:metabolism*; D019084:Fluorescent Antibody Technique, Indirect; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000276:immunology / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000276:immunology; D011518:Proto-Oncogene Proteins
chemical_list: D008164:Luminescent Proteins; C105373:MEN1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D010455:Peptides; D011518:Proto-Oncogene Proteins; D049452:Green Fluorescent Proteins